}

  /**
   * Returns a {@code Future} whose result is taken from this {@code Future} or, if this {@code
   * Future} fails with the given {@code exceptionType}, from the result provided by the {@code
   * fallback}. {@link Function#apply} is not invoked until the primary input has failed, so if the
   * primary input succeeds, it is never invoked. If, during the invocation of {@code fallback}, an

    }
    assertTrue(millisElapsedSince(startTime) >= timeoutMillis);
  }

  /** Fails with message "should throw exception". */
  public void shouldThrow() {
    fail("Should throw exception");
  }

  /** Fails with message "should throw " + exceptionName. */
  public void shouldThrow(String exceptionName) {
    fail("Should throw " + exceptionName);
  }

    @Override
    public synchronized void failed(State from, Throwable failure) {
      assertEquals(from, Iterables.getLast(stateHistory));
      stateHistory.add(State.FAILED);
      assertEquals(State.FAILED, service.state());
      assertEquals(failure, service.failureCause());
      if (from == State.STARTING) {
        try {
          service.awaitRunning();
          fail();
        } catch (IllegalStateException e) {

  static final Exception CHECKED_EXCEPTION = new Exception("mymessage");
  static final Future<String> FAILED_FUTURE_CHECKED_EXCEPTION =
      immediateFailedFuture(CHECKED_EXCEPTION);
  static final RuntimeException UNCHECKED_EXCEPTION = new RuntimeException("mymessage");
  static final Future<String> FAILED_FUTURE_UNCHECKED_EXCEPTION =
      immediateFailedFuture(UNCHECKED_EXCEPTION);

      equalsTester.addEqualityGroup((Object) null);
      fail("Should fail on null reference");
    } catch (NullPointerException e) {
    }
  }

  /** Test equalObjects after adding multiple instances at once with a null */
  public void testAddTwoEqualObjectsAtOnceWithNull() {
    try {
      equalsTester.addEqualityGroup(reference, equalObject1, null);
      fail("Should fail on null equal object");
    } catch (NullPointerException e) {

 * the {@link Futures#catching(ListenableFuture, Class, com.google.common.base.Function,
 * java.util.concurrent.Executor) Futures.catching} family of methods. Those versions have slightly
 * different signatures.
 */
@GwtCompatible(emulated = true)
@J2ktIncompatible // Super-sourced
@ElementTypesAreNonnullByDefault
abstract class GwtFuturesCatchingSpecialization {

  }

  @CollectionFeature.Require({SUPPORTS_ITERATOR_REMOVE, FAILS_FAST_ON_CONCURRENT_MODIFICATION})
  @CollectionSize.Require(SEVERAL)
  public void testRemoveIfSomeMatchesConcurrentWithIteration() {
    try {
      Iterator<E> iterator = collection.iterator();
      assertTrue(collection.removeIf(Predicate.isEqual(samples.e0())));
      iterator.next();
      fail("Expected ConcurrentModificationException");

/**
 * Hidden superclass of {@link FluentFuture} that provides us a place to declare special GWT
 * versions of the {@link FluentFuture#catching(Class, com.google.common.base.Function)
 * FluentFuture.catching} family of methods. Those versions have slightly different signatures.
 */
@ElementTypesAreNonnullByDefault
abstract class GwtFluentFutureCatchingSpecialization<V extends @Nullable Object>
    extends AbstractFuture<V> {
  /*

 *     Guava 27.0
 */
public final class InternalFutures {
  /**
   * Usually returns {@code null} but, if the given {@code Future} has failed, may <i>optionally</i>
   * return the cause of the failure. "Failure" means specifically "completed with an exception"; it
   * does not include "was cancelled." To be explicit: If this method returns a non-null value,
   * then:

    expectAdded(e3());
  }

  @MapFeature.Require({FAILS_FAST_ON_CONCURRENT_MODIFICATION, SUPPORTS_PUT})
  @CollectionSize.Require(absent = ZERO)
  public void testPutAllSomePresentConcurrentWithEntrySetIteration() {
    try {
      Iterator<Entry<K, V>> iterator = getMap().entrySet().iterator();
      putAll(MinimalCollection.of(e3(), e0()));
      iterator.next();
      fail("Expected ConcurrentModificationException");